TITLE: Notation for specifying the fractional part of a number
QUESTION [6 upvotes]: Just like the title says, what is the notation for specifying the fractional part of a number?

REPLY [6 votes]: The fractional part of a number $x$ is usually denoted by $\{x\}$ or $\operatorname{frac}(x)$ (see Wikipedia), i.e. $\{x\}=x-\lfloor x\rfloor$, where $\lfloor \cdot\rfloor$ is the floor function.